The present invention relates to a solid-state electronic circuit placed in contact with a structure. The circuit, which comprises a plurality of redundant connections or branches and nodes, is intrinsically resistant to interruptions of a plurality of interconnections between the nodes, thereby preserving the continuity and functionality of the circuit even in the presence of multiple single interruptions of connections or branches of the same circuit. Continuity and functionality of the circuit are ensured in a high percentage of cases, approx. 99.99%.
Such circuits may have many applications depending on the structure with which they are associated, in particular placed in contact.
The circuits according to the present invention can be associated with panels, e.g. soundproof panels.
Said soundproof panels find application in the aeronautics field.
Soundproof panels are generally formed by multiple layers (sandwich), and comprise two surfaces or skins and one spacer element. Said spacer normally has a honeycomb structure. The surface exposed to the air flow is perforated, in a manner such that a Helmholtz resonator is obtained in each honeycomb cell.
Generally, these soundproof panels are not heated.
Generally, during the flight mission these panels are subject, whether directly or indirectly, to icing.
The evolution of the requirements concerning icing severity and soundproofing anticipated by the flight safety bodies urges to create soundproof panels which are heated, for example, by electronic circuits capable of resisting to interruptions caused by panel perforation. In particular, difficulties are encountered in ensuring continuity of the electric circuit following the panel perforation operations.
The electronic circuits included in soundproof panels, such as, for example, heating elements, are normally buried in a rolled carbon sheet.
In the art are known some devices as described in their respective documents.
U.S. Pat. No. 6,137,083A discloses a heating device comprising electrically conducting longitudinal fibers extending substantially parallel to a leading edge of the aerofoil close to said leading edge, and means for electrically connecting the ends of the longitudinal conducting fibers to an electric power supply. The conducting fibers are grouped together in conducting rovings forming part of a hybrid fabric which furthermore includes a weft of electrically insulating fibers woven together and woven with the conducting rovings.
EP1060645A1 discloses an electronics device comprising a carrier, such as a printed circuit board, a substrate or a chip, and an electric conductor on a surface of the carrier. The surface of the conductor facing away from the carrier has a surface structure in the form of flanges which are defined by etched grooves.
U.S. Pat. No. 7,923,668B2 discloses an engine nacelle inlet lip including both acoustic treatment and electric heating for ice protection. The inlet lip has a composite outer skin and a composite inner skin, with the composite outer skin having at least one integrated heater element embedded in the composite material. An acoustic cellular core positioned between the outer and inner skin acts to attenuate fan noise from the engine. Covering the outer skin and overlying the acoustic core is a perforated erosion shield having a first set of openings that pass entirely thorough its thickness. The composite outer skin includes a second set of openings such that sound waves can pass from an inner barrel portion of the inlet lip through the erosion shield, outer skin, and heater element to the underlying acoustic cellular core.
U.S. Pat. No. 3,216,089A relates to a technique for making electrical circuitry and more particularly to a technique employing preformed elements incorporating conductor elements, a frame and support members which provide mechanical continuity during assembly operations.